Tion of new yoek



R. H. MANSON.

uoox'swncn AND cmcuns mama. APPLICATION FILED DEC. 18, I916.

1,303,351. Patented May 13, 1919.

/1 7T OHNE Y rrnn srATEs PATENT OFFiCE.

RAY H. MANSON, OF ROCHESTER, YORK, ASSIGNOR TO THE STROMBERG-CABLSONTELEPHONE MANUFACTURING COMPANY, OF ROCHESTER, NEW YORK, CORPORA- TIONOF NEW YORK.

HOOKSWITCH aiirn crnoorrs THEitnFon.

Specification of Iiett ers fatent. Patented May 13, 1919.

Application med December 1a, 1916. Serial N6. 137,620.

phone systems to arrange the substation apparatus with circuitconnections so as to secure the maximum of telephonic transmission whenthe subscriber speaks into his telephone transmitter.

These circuit connections, however, while producing the above desiredresults, produce an undesirable result in thatthe side tone effect isincreased; that is, there is reproduced in the telephone receiver of thetransmitting sub-station to an abnormal degree, the sounds which areprojected into the transmitter of that station, the receiver reproducingthese sounds to such an abnormal degree that the various noises of theroom in which the telephone instrument is pla ed will be heard and willdrown out much of the sound in the receiver, due to thefincom ing voicecurrents from the distant station.

Circuits have also been proposed which will not have this excessiveside-tone effect in the receiver but these circuits are invariablyattended by a loss in outgoing transmission.

It is particularly the object of this invention to produce a switchhookcombination which will permit the use of either type of circuit at thewill of the sub-station mstrumerit user, whereby such user can. obtainthe use of a telephonic circuit of high transmitting power, or when thisis not required, can obtain the use of a circuitin which the sidetone isnot so severe, for ordinary local conversations.

Another object of my invention is to provide an improved means foraccomplishing the different switchhook positions whereby differentcircuit connections are caused, so that the same shall be positive inaction, have a'pleasing appearance to the eye, at the same time being ofdurable construction so that it cannot be injured byabuse or by a longcontinued use.

Other objects of my invention and the inventionitself will be apparentfrom the accompanying description V of the embodiment illustrated in thedrawings.

I have shown an embodiment of my invention in the accompanying drawings,inwhich similar reference characters have been used in the differentfigures to designate like parts. i

Figure 1 shows partly in cross-section and partly in side elevation aswitchhook struc ture of an embodiment constructed in accordance with myinvention.

Fig. 2-.N shows an end view of the latch of the switchhook in its normalor unoperated position but illustrated as broken away so as to show thelatch mechanism. a i

Fig. 2O likewise shows the switchhook latch in the intermediate orlatched position and Fig. 2-P likewise shows the switchhook latch in itsreleased or ultimate position.

At 2 A and 2-D I show normal circuit connections of two forms of myinvention at the time the switchhook and latch therefore is in normalposition, as shown in Fig. 2N.

At 3B and 3.E I show the circuit connections of the two forms of myinvention illustrated in Figs. 2A and 2-D, in the intermediate orlatched position of the switchhookas illustrated in Fig. 2().

At l--C and4.F I show the circuit connections of the two forms of myinvention illustrated, in the fully operated or released position of theswitchhook mechanism illustrated in Fig.

. Figs; 2-A, 3-B and 4 Cil1ustrate circuit connections for the useof myinvention in connection with circuits involving the use of what is knownas a direct current receiver; that is, such a receiver as is operatedwith the direct line current passing through its winding.

At Figs. 24), 3-E and 4-1? I illustratelthe use of my invention inconnecti'pn with telephone circuits involving the useof firmly betweenthe latch member, are

the ordinar Y magneto receiver which operates Without the direct batterycurrent from the line passing through its winding.

Fig. 1 shows a side elevation of the parts of the switchhook mechanisminclosed inside the telephone casing; it also shows in cross-section theparts of the switchhook mechanism not inclosed inside the telephonecasing and comprise a portion of a side of the telephone casing and theexternal parts, such as the latch L, etc.

The internal parts comprise a frame f, whereon the switchhook lever H ispivoted at p, the switchhook carries an insulated roller 7, contactingnormally with a lever switch spring 1. is adapted to be moved by theroller 7", and to cause the set of s 'itch springs s to be o-p erated.

A portion of a side of the telephone casing is illustrated at G, anescutcheon plate being mounted on the outside thereof, shown at e, andis secured through the walls of the casing to the frame f, by means ofmachine screws m, and m. The machine screw 972. has a flangedbushing-washer b secured the head of the screw m and the escutcheonplate 6. Pivoted loosely between the flanges of this bushing-washer andadapted to rotate on the same is the latch member L. These externalparts, including perhaps more clearly understood by reference to theviews at 2N, 2O and 2-P which shows a side View of these parts in thedifferent operating positions.

Referring to these latter figures, I provide an inclined cam surface 0for the latch which is engaged by the hook H. This constructioninvolving such a cam surface is important, as by means of this and theprovided construction of the cooperating parts, I am enabled to forciblyreturn the latch member L to normal position as illustrated at 2N fromthe ultimate position as illustrated at 2-P by means of the forciblepropelling of the same by means of the under surface of the switchhooklever H engaging this cam surface. I thus do not depend upon the forceof gravity alone as in prior constructions of such devices with which Iam familiar, wherein dependence-is placed upon the gravity forceovercoming the friction between the mobile part or parts and thestationary parts to which they are secured.

Furthermore, I do not clamp, constructions, the latch member to thecasing or escutcheon plate of the machine screw on but provide anoncorrosive flanged metal bushing 2) upon which the latch member ispivoted loosely, the flanges preventing thescrew from binding'the latchmember L as would otherwise as in prior L directly by means This leverswitch spring occur and as does often occur in prior constructions abovereferred to.

Referring now to Figs. 2-A and 2-N these show the latch member, theswitchhook and the circuit connections in normal or unoperated position.111 Fig. 2A I show the receiver 5 restingupon the switchhook ll therebycausing contacts between the springs 1 and 2 to be made. The connectionbetween the springs l and 3 will be broken, thereby causing the circuitconnections between the line wires 7 and 8 to be discontinuous whichwill cause the signal apparatus, not shown, at the Central Oflice toindicate the non-busy condition of the line.

Now, if the subscriber desires to place the apparatus in conversationalcircuit with the central office equipment the receiver 5 will be removedfrom the switchhook lever H- causing the lever H to take the positionindicated in Fig. 2-0, the latch member L. by its latching tongue 9,preventing the lever from rising any further at this time. Theconversational circuit between the line wires 7 and 8 is now closed, thecircuit cans ing this closing being traced as follows: From line wire 7through the transmitter 10. contacts springs 3, l and 2, conductors l1and 12, receiver 5, to the other line wire at 8. It will thus be seenthat the primary winding 13 of the induction coil 14 is not in circuitand the secondary winding 15 of the induction coil is short-circuitedand thus disabled by the closure of the contacts of the springs l and 2.

The circuit then briefly consists of the conducting wires, thetransn'litter and the receiver in serial circuit with the line wires.This provides a circuit in which the transmission is not as efficient asthat which will later be described but in which the sidetone effect isminimized producing an agreeable effect to the telephone user whopresumably, when using this circuit, does not need the highest degree oftransn'iission efliciency but is possibly using the line to conversewith nearby stations in which such high degree of transmission isunnecessary.

uch conversational circuits wherein the stations are not far apart,exceed in number those in which the stations are far distant from eachother and therefore. in a majority of cases, the circuit connections, asshown in Fig. 3-B and with the latch member in the position shown at 2-Owill be used.

For long distance connections, however, where the parties are apart adistance one from the other, a more eflicient sub-station transmittingcircuit is highly desirable. Such a circuit can be readily obtained byoperating, manually, the latch member L, so that the switchhook lever Hadvances to its ultimate or extreme operating position and the latchtaking the ultimate position as shown in Fig. 2-P. The circuits willthen be as shown in Fig. l--C which shows the springs 1, 3 and 41through their contacts making electrical connection one with the other,and breaking the circuit between the contacts of springs 1 and 2. Thusthe short circuit is removed from the secondary winding 15 of theinduction coil 14, and the primary winding 13 is connected inconversational circuit in series with the condenser 16, acrosstransmitter 10. Under this condition the well known Booster sub stationcircuit is formed in which as is well known the outgoing transmission isquite powerful, this circuit being well known in the art, and it is notnecessary to describe the same in detail. In this use of the Boostercircuit the direct current receiver 5, is connected serially in the linewire 8.

Figs. 2D, 3E and 1-F show an embodiment of my invention wherein amagneto type receiver is used, and it is, there fore, not connectedserially in the line as in the circuits just described, but is connectedin series with the condenser 16, and the primary winding 13 of theinduction coil 14. Fig. 2D show-s the circuit connection with thereceiver 5 on the hook, and the circuit connection between the linewires 7 and 8- being disconnected on account of the open contacts of theswitch springs 17 18 and 19.

, When the circuit is taken for use the subscriber removes the receiver5 from the switchhook, and with the latch and hook members in theposition shown in Fig. 2-0, the circuit connections are as illustratedin Fig. 3E. The switch springs 19 and 20 are un'operated, and throughtheir contacts remain in connection one with the other. The switchsprings 17 and 18 make connection through their contacts at this time,completing the circuit for the transmitter 10, between the line wires 7and 8.

The circuit then briefly consists of a conducting wire leading from linewire 7 from the transmitter 10 through switchhook contacts of thesprings 17 and 18, the winding 15 of the induction coil 14, whichwinding in this case is a primary winding, to the other line wire 8. Thereceiver 5 is connected in a local circuit consisting of a winding 13 ofthe induction coil, which winding in this case is a secondary winding,the condenser 16, the conducting wire 21, the switch spring 20, theswitch spring 19, and the conducting wire leading back to the receiver5. Thus, the circuit with the hookswitch latched as in Fig. 2O is thatof an induction. coil circuit well known in art, having a localreceiving circuit, and while fairly efficient for receiving, is not soefficient for outgoing transmission. The sidetone efiect is less thanin. the form to be described which has a high efficiency for outgoingtransmission as will later be discussed. The circuit just described,would just as in the case of the circuit shown in Fig. 3-B have aconsiderable use for local conversational. telephone circuits whereinpowerful transmission is not an object, but wherein the side-tone effectis especially undesirable.

Now, should the subscriber desireto obtain the use of a circuitpossessing the highest degree of outgoing transmission efficiency as forlong distance connections, he will depress, manually, the latch member Lto the 'iposition shown in 2-1, allowing as shown in this figure thehookswitch lever H toadvance .tOI its highest or ultimate position.Under this condition the circuit connecti-ons illustrated in Fig. 4Fform the well known Booster circuit, and which is briefly described asfollows :-In this circuit the winding 15 becomes a secondary winding,and the winding 13 primary winding of the induction coil 14:. a

The contacts of the springs 17, 18 and 19 making electrical connectionsone with the other cause the conversational circuits to be closedthrough these contacts. The receiver 5 is now shown serially connectedwith the condenser 16, and the primary Winding 13 across the transmitter10. When the subscriber speaks into the transmitter, the' transmittervarying its resistance will vary the potential at its terminals andthereby vary the charge of the condenser 16, as well varying the linecurrent directly. This effect causes a varying current to flow throughthe primary winding 13, which is repro duced in the winding 15 in thewell known manner augmenting the effect of the varying current in theline above mentioned. This produces very powerful undulations ofcurrents in the line wires causing the well known so-called Boostereffect on outgoing transmission, but at the same time creating a veryconsiderable undulating or varying current to flow through the receiver5, producing a considerable side-tone effect in this receiver. For thisreason this powerful transmission circuit would only be used for longdistance connections, and would not be used in the majority ofconnections.

I have above described the various illustrated hook and latch positionsand the circuits resulting therefrom, from the normal position to theultimate position of the switchhook and latch. When the subscriberfinishes the telephonic conversation, he will replace his receiver uponthe hookswitch lever and cause it to descend. The bottom of the leverduring its downward movement will come into an engagement with the camsurface 0 of the latch member, forcing the latch member forward, and itsface portion downward until it is restored to its normal position asshown in Fig. 2N, from the ultimate position as shown in Fig. 2-1

I am aware that numerous and extensive departures can be made from theembodiments shown herein and described above. such embodiments beingillustrated so that my invention can be more clearly understood, and notfor the purpose of limiting the same.

What I claim is 1. In a telephone substation, telephone elementstherefor, a plurality of circuits for said elements, one of saidcircuits being adaptable to produce high efliciency telephonictransmission, another circuit being adaptable to produce a lessetlicient telephonic transmission, switch springs adapted by theirmovement to switch the telephone elements to either of said circuits, alever member for said switch springs, a latch for said lever member,said latch controlling the position of said lever to cause the levermember to operate the switch springs to make proper connections foreither of said circuits.

2. In a switchhook circuit, a switchhook,

a lever member therefor having a plurality of operative positions and anormal position. switch springs operated by said lever to make differentelectrical connections at each operative position said switch springsdisengaged when in normal position, a latch to retain said switch leverin one of said operative positions, manually operated means integralwith said latch to cause said lever to take a second operative position,a relatively low efficiency telephone circuit, a relatively highefiiciency telephone circuit, said low eliiciency circuit being formedby said first connections and said high efliciency circuit being formedby second connections.

In a telephone, a switchhook therefor, a booster circuit therefor, ananti-side tone circuit therefor, an automatically operated lever forsaid switchhook to connect said booster circuit to the line Wires ofsaid telephone, or to connect said anti-side tone circuit to said linewires, said lever automatically operated to connect said anti-side tonecircuit, and manually operated to connect said booster circuit.

4:. In a telephone substation instrument, a telephone receiver therefor,supporting means for the said telephone receiver,

spring means to move the said supporting neans when the said receiver isremoved from the said supporting means, a plurality of sets ofelectrical contacts. means to cause one of the said sets of contacts tobe operated by the moving of the said supporting iii-cans to connect in(Oil\tlfSliilUlEl!i circuit the transin'ssion cicnuni's of the saidtelephone according to a given manner of connections for outgoing andincoming tolephonic transmission, stop means to stop the said support inthe said movement. at a point where it fails to operate the second setof contacts, the said step means being capable of manual operation tocause the said supporting 11192 as to continue its movement to aposition wherein the second set of contacts are operated, operation ofthe second set of contacts ch ti o; the manner of connection thetransmission elements of the said telephone to produce a different opcrative transmission eiiect for incoming and transmission.

5. In a telephone substation instrument, a telephone receiver therefor,a telephone transmitter therefor. an induction coil and condenser withcircuit conductors counccting the said receiver, transmitter, inductioncoil and condenser to connect the same in a given manner to produce agiven effect for incoming and outgoing telephonic transmission,supporting means for the said telephone receiver, motor means to movethe sa d supporting means when the said receirer is removed from thesaid supporting means, a plurality of sets of electrical con tacts inthe said circuit conductors, means to cause one of the said sets ofcontacts to be operated by the moving of the said supporting means toconnect in c mversatio1uil circuit the transmission elements of the saidtelephone according to the above manner of connections, and manuallyoperated means to extend the movement of the said supporting means tocause the said second set of electrical contacts to be operated. theoperation of the second set of contacts altering the circuit connectionsbetween the telephone elements to produce a different operativetransmission effect between the said transmitter and the said receiver,and for incoming and outgoing transmission.

In witness whereof. I hereunto subscribe my name this 16th day ofNovember, A. D

the

RAY H. MANSON.

Copies of this patent may be obtained for five cents each, by addiessingthe Commissioner of Patents,

Washington, I). C.

